“It’s truly a fundamental shift in how people are moving about their communities,” says Michael Melaniphy, the group’s president and CEO, noting the growth started several years ago.

“Initially, when fuel prices spiked, it drove people to transit, and once they came, they decided it was good, and they stayed.”

There is a correlation, Melaniphy says, between high ridership and the health of the U.S. economy. Sixty percent of trips taken on public transit are work commutes.

However, Michael Moss, who directs the Rudin Center for Transportation Policy and Management at New York University, argues the other 40 percent is also important:

“Mass transit today is not just a peak-hour activity,” he says. As public transportation becomes more popular, and as cities spend more money on expanding it, transit systems are opening earlier and closing later.

“There was a time when you said, ‘I want to live near a good school district,’” Moss says. “Today, people want to live near a good transit connection.”

Moss is referring to young people especially, who are ever less likely to own cars.